DNS Message Resource Record Field Formats

As you've learned in this and the previous chapter, the exchange of information in DNS consists of a series of client/server transactions. Clients send requests, or queries, to servers, and the servers send back responses. DNS servers are database servers, and they store DNS name database information in the form of RRs. The questions asked by clients are requests for information from a DNS server's database, and they are answered by the DNS server looking up the requested RRs and putting them into the DNS response message.

The Answer, Authority, and Additional sections of the overall DNS message format are the places where servers put DNS RRs to be sent back to a client. Each section consists of zero or ...

Get TCP/IP Guide now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.